Manufacturing will end in 2017, but Holden managing director Mike Devereux says he expects the factory to remain busy until then.

"We will do this (closure) in as orderly a fashion as we can and and we will be very aggressive in marketing our cars so we can continue to produce them in our Elizabeth facility as at high a rate of production as possible right until the last car rolls off the assembly line," he said.

South Australian Premier Jay Weatherill says he is worried people might stop buying Holdens and force an earlier winding down of production.

"I have my own advice and analysis that suggests it could be earlier and we need to prepare for that," he said.

The CEO of welfare agency Anglicare, Peter Sandeman, says the knock-on effect of Holden's closure will be immense for the families of northern Adelaide.

"We believe families are going to be under great pressures, there'll be family breakdowns, more domestic violence, more homelessness, more truancy, drug abuse and unfortunately people will turn to gambling and things like that to take their minds off their situation," he said.

He is urging people to think now about what they can do to help avert future hardship, whether they be workers or those whose businesses rely on the people of the northern suburbs.

"If they've got any debt they should be paying that down immediately," he said.

"If they're in any doubt they should see a financial counsellor, now is the time to act, now is the time to plan.

"The silver lining in all this is we now have certainty into what's going to happen."

"We know that it will have an impact on our local shopping centres, on parents' ability to pay for childcare fees and for school fees, the ability to go out and spend money in our local economy," he said.

"We just don't know at this stage how many of those workers will be able to get jobs moving forward."

Neighbouring Salisbury Mayor Gillian Aldridge said four years of hard work now faced authorities and local communities to prepare for life beyond Holden.

"We're just in the beginning of sitting on those committees and trying to work through what we can do. We're certainly not ready for it just yet," she said.

The Chamber of Mines and Energy thinks the mining sector might have jobs for some Holden employees.

Chamber CEO Jason Kuchel says some workers would have inherent skills suited to mining work and others could be trained.

"If the Government can do something quickly about desperately needed infrastructure to advance minerals projects then there is the possibility that some of these workers could be taken up in the resources sector," he said.

"But [without government backing] these projects will take too long for many of these workers unfortunately."